Railway traffic controlling apparatus



war/v M. A. PENROD S 14 [Jr- 27 (20:50 JECT/O/V T0 1?! orpouvrpOCC'UP/ED.

INVENTORZ M H Pe nro Original Filed March 26 Fig]. 20

Si 0 w RAILWAY TRAFFIC CONTROLLING APPARATUS Sept. 12, 1933.

Patented Sept. 12, 1933 RAILWAY TRAFFIC CONTROLLING APPARATUS Melvin A.Penrod, Murrysville, Pa., assignor' to The Union Switch& Signal Company,Swissvale, Pa., a corporation of Pennsylvania Application 11 Claims.

My invention relates to railway traffic controlling apparatus, andparticularly to apparatus for controlling traffic'governing devices,such as railway track switches, by levers which are located at a centralpoint such as an interlocking tower.

One feature of my invention is the provision of means for controllingthe movement of a switch in accordance with traffic conditions inadvance of the switch.

I will describe two forms of apparatus embodying my invention, and willthen point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a diagrammatic view illustrating.one form of apparatus embodying my invention. Fig. 2 is a similar viewshowing a modified form of a'portion of the apparatus of Fig. 1, andalso embodying my invention.

Similar reference characters refer to similar parts in both views.

Referring first to Fig. 1 of the drawing, the reference characters land1 designate the track rails of a stretch of railway track X, which isdivided, by means of insulated joints 2, into a plurality of track.sections Al3, B0 and CD. A second track Y is connected with the track Xby means of a switch G located in section B-C, and the rails 1 and 1thereof are divided, by

insulated joints 3, to form a section E- -F. Each of thesections A B,B-C, CD and is provided with a track circuit which is supplied withcurrent by a track battery 4 connected across the rails adjacent one endof the section, and

which includes a track relay, designated by the reference character Rhaving a distinguishing exponent corresponding to its location,connected across the rails adjacent the opposite end of the section. Thesection of the track Y between the point F and the switch G is includedin the track circuit of the section BC by a conductor 5 connectingtherails 1 and l 'of the tracksX and Y, respectively.

The entrance of a westbound train into the section C-D is controlled bya signal S and by an automatic train stopping device 6, and its movementover the switch G is controlled by signals S and S In a like manner themovementof 5 a westbound train from the section 'A-B of the main track Xor from the section E-F of, the track Y is controlled by signals S and Sre.- spectively. Also, the movement of an eastbound trainover the switchG from the section A B of the track X'or from'the section EF of theMarch-26, 1930, Serial No. 438,995 Renewed June 8, 1932 track Y iscontrolled by the usual dwarf signals S and S respectively.

Switch G is controlled by an operating mechanism J which is in turncontrolled by a manually operable lever v 'which is located at a remote6Q point,-such as an interlocking tower, and which is movable between anormal position 12, indicated by full lines in the drawing, and areverse position r, indicated by broken lines in this view. The lever Voperates an arm 7 which engages a contact '7" when the lever occupiesits normal or 12 position and a contact 7 when the lever occupies itsreverse or 1' position. The lever V also operates an arm 8 which engagesa contact 8" when the lever occupies its normal or n position and acontact 8 when the lever occupies its reverse or 7' position. By meansof this lever the towerman may operate the mechanism J so as to move theswitch G between its normal and reverse position. Under certain trackwayconditions, hereinafter to be described, the lever V will be locked inits normal position by a latch 9 00- operating with a locking segment 10and under certain other trackway conditions this lever will be locked inits reverse. position by a latch 11 Q cooperating with a locking segment12. The segments 10 and 12 are both mounted on the same shaft on whichthe lever ,V is mounted, which shaft may constitute part of aninterlocking mas chine of the usual type, and the latches 9 and 11 areoperated to engage and disengage the segments by a lock magnet Lwhich iscontrolled by a control relay K.

The signal S and. the train stopping device 6 are controlled by a leverV which may be located in the interlocking tower, through. the medium ofa relay T, and also by a circuit controller H comprising a contact 13-14closed at all times except when the switch G occupies its reverseposition, and a contact 13-15 closed at all times except when the switchoccupies its normal position. The lever V moves between a normalposition 11 and a reverse position 2' and operates a contact 16, acontact 17 and a slowacting contact l8. When the lever V occupies m0 itsnormal position 41, in which it is illustrated in the drawing, contact16 is open, the contact 17 is closed, and the slow-acting contact l8 isalso closed. When, however, the lever V is moved to its reverse position1*, contact 16 is closed, and contacts 17 and 18 are opened. Theslow-acting contact 18 is of the type that opens quickly when the leverV is moved to its reverse position but requires a predetermined intervalof time after the lever V is returned to its normal position before thiscontact is closed. One form of device which may be used to operate thiscontact is disclosed in Letters Patent of the United States No.1,157,960, granted to H. 13. Post on October 26, 1915. When levers V andV both occupy their n positions and relay R is energized, the controlrelay K is energized by current traversing three different circuitsthereby maintaining its contacts 19 and 20 closed. Current in the firstof these circuits flows from terminal a: of a suitable source ofelectrical energy not shown in the drawing, through contact 8-8 of leverV front contact 21 of track relay R and winding of relay K to the otherterminal 0 of the same source. Current in the secondof these circuitsflows from terminal as, through slow-acting contact 18 of lever V andwinding of relay K to terminal 0. The third circuit is a stick circuitfor the control relay K through which current fiows from terminal a",through contact 17 of lever V contact 19 of control relay K, and thewinding of this relay to terminal 0. As hereinbefore mentioned, theenergization of the relay K maintains the contact 20 thereof closed, andconsequently the lock magnet L will be energized by current flowing fromterminal 0:, through a front contact 22 of track relay R contact 20 ofcontrol relay K, and winding of lock magnet L to terminal 0. Theenergization of magnet L maintains the latches 9 and 11 out ofengagement with the segments 10 and 12, thereby permitting operation ofthe switchlever V to its reverse position should the towerman desire toreverse the switch G.

I will now assume that the towerman desires to move the signal S to itsclear position, and the automatic train stopping device 6 to anineffective position in order to allow a westbound through train to passover the track X. Under such circumstances he swings the signal lever Vto the right, as viewed in Fig. l, to its reverse position 1", therebyopening the contacts 1'? and 18 and closing the contact 16. The openingof the contacts 1'7 and 18 breaks the circuits through these contactswhich energized the relay K jointly with the circuit through the contact8-8 of the lever V but inasmuch as contact 8---8 of lever V is closed,the circuit for relay K through this contact remains closed and as aconsequence the relay K remains energized. The closing of the contact 16by the above-described movement of the leverV establishes a circuit fromthe terminal a: through contact 16 of lever V front contact 23 of trackrelay R contact l .-13 of circuit controller H, front contact 24 oftrack relay R front contact 25 of track relay R and winding. of relay Tto terminal 0. The current in this circuit energizes the relay T andcauses it to close its front contacts 26 and 27 and establish twoseparate circuits Current in the first of these circuits flows fromterminal as, through contact 26 of relay T, and the operating mechanismof signal S to terminal 0, thereby causing the signal S to assume itsclear position; The current in the second of these circuits flows fromterminal m, through contact 2'? of relay T and the mechanism of theautomatic train stopping device 6 to terminal 0, and causes the device 6to assume its ineifective position.

As the train enters the section CD from the east the track relay R isdeenergized, thereby releasing its front contact 25, and breaking thecircuit previously traced through the relay T thus causing this relay tobecome deenergized. This causes the signal S to again display a stopindication to succeeding trains. The deenerg'ization of track relay Ralso causes a contact 28 thereof to close and to establish a circuitfrom terminal x, through back contact 28 of track relay R contact 29,and operating mechanism of the automatic train stopping device 6 toterminal 0. Contact 29 is closed when the section to the right of pointD is occupied, and the circuit just traced therefore prevents device 6from resuming its normal effective position while the train'is passingover it, that is, while the train occupies both section CD and thesection to the rightof this section.

As soon as the train enters section B-'-C, the track relay It becomesdeenergized and opens its front contacts22 and 24. The opening of thecontact 22 breaks the circuit previously traced, which maintains thelock magnet L energized and causesthe release of the latches 9 and 11.The notch in the segment 10, being in registry with the latch 9 at thistime is engaged thereby and prevents theleverman from operating thelever V to reverse the switch G while the train is passing over theswitch and as long as it occupies'the section 'B-C.

When the train leaves section CD the track relay R becomes reenergizedand closes its contact 25 but by reason of the fact that the contact 24of relay R is now open the circuit through the relay T remains open andthe signal S continues to display'a stop indication. The energization oftrack relay R also opens its contact 28 thereby opening the circuitpreviously traced through this contact and the contact 29 whichmaintains the automatic train stopping device 6 ineffective and permitsthis device to resume itsnormal active position for succeeding trains.

As soon as the train enters section A-B the track relay R becomesdeenergized, and opens its front contact 23, thereby creating anotherbreak in the circuit of the signal control relay T previously tracedthrough this contact. As a result the signal relay T will not becomeenergized by the closing of contact 24 when the track relay R becomesenergized upon the departure of the train from section B-C. The signal Sthereforecontinues to display a stop indication. When the train leavessection BC, the energization of track relay R causes its front contact22 to close, thereby reestabling the circuit through the lock magnet L.This causes the latch 9 to move out of engagement with the segment 10 soas to. permit the leverman to move the switch G to its reverse positionif he so desires.

' As soon as the train passes out of section A-B, the track relay Ragain becomes energized and closes its front contact 23, therebycompleting the circuit through the signal relay T and causing it toclose its contacts 26 and 27. This will again complete the circuitscontrolling the signal S and the train stopping device 6 and cause theformer to display a clear indication and the latter to assume itsineffective position.

If, now, the towerman swings the lever V back to its normal position nthe contact 16 operated thereby will open and break the circuittherethrough which caused the energization of the signal relay T. Thecontacts 26 and 27 of the relay T will therefore again open and breakthe circuits therethrough. This will cause the signal S to display astop indication and the train stopping device to assume its normalactive position. The system is now in its initial condition, as shown'inFig. 1.

I will nowassume that the towerman desires to route a westboundtrainifrom the track X to the track Y. He, therefore, swings the switchlever V to the right to its 1 position, thereby opening the contact '7-7and closing the contact '77 The closing of contact '7--7 causes theenergization of the switch operating-mechanism J and moves the switch Gto its reverse position. The above described movement of the lever Valso opens the contact 88"' and closes the contact 88 The opening or"the contact 8S breaks the circuit through this contact, the contact 21of track R and the winding of relay K, but the stick circuit through thecontact 17 of lever V and the circuit through the slow-acting contact 18remain intact, so that relay K remains energized. The closing of thecontact 8-8 establishes an additional circuit for the relay K throughfront contact 30 of track relay R The movement of the switch G from itsnormal to its reverse position opens contact 1314 and closes contact1315 of the circuit controller l-I. p

The towerman now swings thelever V to its reverse or 1' position therebyclosing its contact 16 and opening both of its other contacts 17 and 18.The closing of contact 16 establishes a circuit from terminal a: throughcontact 16 of lever V front contact 31 of track relay R contact 1315 ofcircuit controller, front contact 24 of trackrelay R front contact 25 oftrack relay R and winding of relay T to terminal 0. The energization ofthis relay closes its contacts 26 and 2'7 and causes the signal S todisplay a clear indication and the automatic train stopping device 6 toassume an ineifective position as hereinbefore described. The opening ofcontacts 17 and 18 of lever V breaks the circuits through these contactswhich energizes the control relay K leaving this relay energized by. theadditional circuit hereinbefore traced through the contact 8-8 1 oflever V and front contact 30 of track relay R When a westbound trainenters section C-D the track relay R becomes deenergized. This opensfront contact 25, and deenergizes relay- T with the result that thecontacts 26 and 27 thereof open and interrupt the circuits therethroughrThe result of this is that the signal S is caused to again display astop indication but the train stopping device 6 is maintained in itsineffective position by the circuit through back contact 28 of relay Rand contact 29.

Upon the entry of the train into section 3-0 the track relay R becomesdeenergized and opens its front contacts 24 and 22. The opening ofcontact 22 causes deenergization of lock relay L and permits its latch11 to move into locking engagement with the associated segment 12,thereby preventing the switch lever V from being operated to return theswitch G to normal as long as any portion of the train occupies sectionB C. As the train departs from section CD the track relay R againbecomes energized and closes its front contact 25 and opens its backcontact 28, but by reason of the fact that the contact 24 ofthe trackrelay R is open, the circuit through the relay T is held open. Theopening of the contact 28 breaks the circuit that holds the device 6ineffective and therefore this device resumes its normal operativeposition for succeeding trains.

The train next proceeds over the switch G and enters section E-F oftrack Y immediately c ausing the deenergization of track relay R As thetrain departs from section BC the track relay R again becomes energizedand closes its contacts 24 and 22 but inasmuchas the front contact 31 ofrelay R is now open, the circuit for relayT is held open. The signal Stherefore remains at stop. The closing of contact 22 of track relay Rhowever, reestablishes the circuit through the lock magnet L and causesit to move the latch 11 out of engagement with the segment 12. lever Vmay now be operated to return the switch to normal if so desired.

It will be noted that the switch lever V is locked against movement sothat it is impossible to return the switch G to its normal position, aslong i the switch G- from being moved from normal to reverse after awestbound train has entered section CD upon a clear? indication of thesignal S and the possibility of derailment occa sioned thereby. Forexample, I will assume that section EF of track Y is occupied by a west-The bound train and that the switch G has been re- 7 turned to itsnormal position and the signal 5 displays a clear indication forwestbound trafiic 7 yer track X. Under these conditions I will alsoassume that another westbound train enters section C-D and that thetowerman desires for some reason to switch the second train onto thetrack Y occupi d by the first train. The switch 1 G is however locked inits normal position by reason of the fact that the contacts l7, 19, 18and 21, which independently control the energization of lock magnet Lare all open. The towerman can not close contact 21 because the trackrelay R which controls this contact is deenergized due to the presenceof the first train in section EF. He

can not cause the energization of the lock magnet L by closing contact17 because the contact 19 J in this stick circuit is open due to thedeenergization of the magnet K. The towerman, therefore, must firstreturn the signal lever V to its normal position thereby releasing theslow-closing contact 18. The time interval of this contact is ofsufficient duration to permit the second train to 1 pass the switchentirely if it is a fast moving train that does not have time to stopbefore crossing the switch or if although having sufficient time tostop, disregards the signal. The time interval is,

however, of suificient duration to permit the train to come to acomplete stop before it reaches the switch G if the engineer of thewestbound train 7 obeys the signal S and is not running at too great aspeed. If the second train stops before reaching the switch G thecircuit through con: 5

tact 18 will be established at the expiration of the time interval andthe control relay K will be energized and close contact 20, therebycausing the energization of the lock magnet L, as previously described.This will cause the release of the switch lever V and permit thetowerman to move the switch G to its reverse position. The second trainmay then proceed onto the track Y at reduced speed.

I will now assume that an eastbound train, is

approaching section E-F oftrack Y and that the switch G- occupies itsnormal position and that the signal S displays a clear indication forwest-v bound trains over the track X. Under such conit ons ihece i l eav is ne 'siz n b current in the circuit controlled by contact 21 oftrack relay R and contact 8-8 of switch lever V Consequently, if theeastbound train should enter section E-F before the towerman reversesthe switch G, the track relay R already having become deenergized andopened its front contact 21, relay K will have become deenergized andopened its front contact 20, thereby deenergizing the lock magnet L andpreventing the subsequent operation of the switch lever V Also, if thetowerman should first move the signal lever V to its normal position inorder to cause the signal S to display a stop indication to westboundtraffic, the slow-acting contact 18 might not close before the eastboundtrain enters section EF. As a result the control relay K would becomedeenergized and cause the switch lever V to be locked in its normalposition as above described.

I avoid the above mentioned difficulty by the provision of the stickcircuit controlled by the contact 17 of the signal lever V and thecontact 19 of the control relay K. By means of this circuit the towermancan prevent the deenergization of the relay K if he moves the signallever V to it normal position and thereby closes the contact 17, whilethe relay K is still energized by current traversing the circuitcontrolled by the contacts 7 and 21. If the eastbound train new enterssection E F anddeenergizes the track relay R the control relay K willnotbecome deenergized through the delayed closing of slowacting contact18. The switch lever V is therefore maintained in an unlocked conditionthereby permitting the towerman to move the switch G to normal at hisconvenience.

In Figure 2 I have shown another form of my invention for delaying theenergization of the control relay K and the unlocking of the switch Gwhen it is desired to reverse the switch while the section E-F isoccupied. In'this arrangement the slow-acting contact 18 shown in Fig. 1is omitted and a contact 32 operated by a slow pick-up relay Msubstituted therefor. The relay M is controlled by a contact 33 operatedby track relay R and is provided with a second contact 34 which isclosed only when the relay M is de energized and which is interposed inthe signal circuit between the circuit controller 5 and the contact 24of track relay B In all other particulars the arrangement shown'in Fig;2 is the same as that disclosed in Fig. land therefore much of thecorresponding apparatus has been omitted from the drawing. With thearrangement above described I will again assume that the section E-F isoccupied, that the switch G is in its normal position, and that thesignal S displays a clear indication to westbound traffic over track X.

If a westbound train now enters section C-D the track relay R willbecome deenergized and open its front contact 25, thereby breaking thesignal circuit and causing the signal S to display a stop indication tosucceeding trains, as hereinbefore described. The deenergization oftrack relay R also closes its back contact 33, thereby completing acircuit from terminal a: through contact 33 and winding of slow pick-uprelay M to terminal 0. This causes the energization of slow pick-uprelay M but by reason of its slow-acting characteristics it will notclose its contact 32 until the expiration of a predetermined timeinterval; As a result, the circuit through this contact 32 whichcontrols the energization of control relay K is notimmediatelyestablished and the contact 20 controlled by this relay remains open.This prevents the immediate energization of the lock relay L andmaintains the switch G locked in its normal position until theexpiration of the time interval required for the slow pick-up relay M toclose its contact 32. in the system shown in Fig. 1, this time intervalis of sufiicient duration to permit the westbound train to pass entirelyover the switch G before the switch actuating mechanism is unlocked,thereby eliminating the danger of moving the switch beneath the train inthe event that the towerman. should make a sudden decision to reversethe switch without giving the train sufficient time to stop or in theevent that the train should disregard the signal and proceed over theswitch.

If, however, the towerman decides in due time to route the train ontotrack Y for some reason,

he first actuates the signals S and S by means forming no part of mypresent invention to indicate such fact in time to permit the train tostop before reaching the switch G. At the expiration of the timeinterval after deenergization of relay E above mentioned the contact 32of the slow pick-up relay M closes, thereby completing a circuit throughthe control relay K. The energization of control relay K causes thecontact 20 controlled thereby'to close and to complete the circuitpreviously traced through the lock magnet L. This causes theenergization of the lock magnet and causes it to elevate the latch 9 outof engagement with its associated locking segment 10 and release theswitch lever V The towerman may now operate the lever V to reverse theswitch as hereinbefore described.

From the foregoing it will be apparent that I have provided a verysimple and convenient apparatus for controlling the operation of a trackswitch in accordance with the condition of the track both in front ofand beyond the switch whereby the danger of moving a switch beneath atrain is to a large extent eliminated.

Although I have herein shown and described only two forms of apparatusembodying my invention, it is understood that various changes andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my inven tion.

Having thus described my invention, what I claim is: a

1. In combination, a plurality of tracks each divided into a pluralityof sections, a track switch located in one of said sections forconnecting said tracks, switch operating means for moving said switchbetween normal and reverse positions, a lever for controlling saidoperating means, lock mechanism for controlling the operation of saidlever, electromagnetic means for controlling the operation of saidlockinechanism, a control re lay for controlling the operation of saidelectromagnetic means, a first contact adapted to be closed when saidlever is moved to a normal position for controlling said control relay,a second contact adapted to be closed when said lever is moved to areverse position for controlling said control relay jointly with saidfirst contact, a

track relay associated with one of said sections a of one of said tracksfor controlling said control relay jointly with saidfirst contact, atrack relay associated with one of said sections of another of saidtracks for controllingsaid control relay jointly with said secondcontact, and means As in the case of the slow-acting contact 18 for attimes controlling said control relay independently of said first andsecond contacts and said track relays.

2. In combination, a pluralityof tracks each divided into a plurality ofsections, a track switch located in one of said sections for connectingsaid tracks, switch operating 'meansfor moving said switch betweennormal andreverse positions, a lever for controlling said operatingmeans, lock mechanism for controlling the operation of said lever,electromagnetic means for controlling the operation of said lockmechanism, a control relay for controlling the operation of saidelectromagnetic means, a first contact adapted to be closed when saidlever is moved to a normal position iorcontrolling said control relay, asecond contact adapted to be closed when said lever is moved 'to areverse position for controllingsaid control relay jointly with saidfirst contact, a track relay associated with one of said sections of oneof said tracks for controlling said control relay jointly with. saidfirst contact, a track relay associated with one of said sections ofanother of said tracks for controlling said control relay jointly withsaid second contact, and a stick circuit including a third contact forat times controlling said control relay independently of said first andsecond contacts and said track relays.

3. In combination, a plurality of tracks each divided into a pluralityof sections, a track switch located in one of said sections forconnecting said tracks, switch operating means for moving said switchbetween normal and reverse positions, a lever for controlling saidoperating means, lock mechanism for controlling the operation of saidlever, electromagnetic means for controlling the operation of said lockmechanism, a control relay for controllingthe operation of said electromagnetic means, a first contact adapted to be closed when said lever ismoved to a normal position for controlling said control relay, a secondcontact adapted to be closed when saidlever is moved to a reverseposition for controlling said control relay jointly witlrsaid firstcontact, a track relay associated withone of said sections of one ofsaid tracks for controlling said control relay jointly with said firstcontact, a track relay associated with one of said sections or" anotherof said tracks for controlling said control'relay jointly with saidsecond contact, a signal for controlling traffic over said tracks,signal controlling means for causing said signal to display clear andstop indications, and a third contact adapted to be operated when saidsignal controlling means is operated for controlling said control relayindependently of said first and second contacts and said track relays.

4. In combination, a plurality of tracks each divided into a pluralityof sections, a track switch located in one of said sections forconnecting said tracks, switch operating means for moving said switchbetween normal and reverse positions, a lever for controlling saidoperating means, lock mechanism for controlling the operation of saidlever, electromagnetic means for controlling the operation of saidlockmechanism, a control relay for controlling the operation of saidelectromagnetic means, a first contact adapted to be closed only whensaid lever is moved to its normal position, a second contact adapted tobe closed only when said lever is moved to its reverse position, a trackrelay associated with one of said sections of one of said tracks on oneside of said switch, a second track relay associated with another ofsaid sections of-auother of said tracks on the same side of said switch,a first control circuit including said first contact and a front contactor" said first track relay for controlling said control relay, a secondcontrol circuit including said second contact and a front contact ofsaid second track relay for controlling said control relay, and aslow-acting contact for at times controlling said control relayindependently of said first and second control circuits.

5. In combination, a plurality of tracks each divided into a pluralityof sections, a track switch located one of said sections for connectingsaid tracks, switch operating means for moving said switch betweennormal and reverse positions, a lever for controlling said operatingmeans, lock mechanism for controlling the operation of said lever,electromagnetic means for controlling the operation of said lockmechanism, a control relay for controlling the operation of saidelectromagnetic means, a first contact adapted to be closed only whensaid lever is moved to its normal position, a second contact adapted tobe closed only when said lever is moved to its reverse position,

a track relay associated with one of said sections 1 of one of saidtracks on one side of said switch, a second track relay associated withanother 01 said sections of another of said tracks on the same side ofsaid switch, a first control circuit including said first contact and afront contact 1 of said first track relay for controlling said controlrelay, a second control circuit including said second contact and afront contact of said second track relay for controlling said controlrelay, a signal for indicating the condition of said 1 tracks, signalcontrolling means for causing said signal to display clear and stopindications, and a slow-acting contact operated by said signalcontrolling means for controlling said control relay independently ofsaid first and second con- 1 trol circuits.

6. In combination, a plurality of tracks each divided'into a pluralityof sections, a track switch located in one of said sections forconnecting, said tracks, switch operating means for moving said 1 switchbetween normal and reverse positions, a lever for controlling saidoperating means, lock mechanism for controlling the operation of saidlever, electromagnetic means for controlling the operation of said lockmechanism, a control relay 1 for controlling the operation of saidelectromagnetic means, a first contactto be closed only when said leveris moved to its normal position, a second contact adapted to be closedonly when said lever is moved to its reverse position, a track relayassociated with one of said sections of one of said tracks on one sideof said switch, a second track relay associated with another of saidsections of another of said tracks on the same side I of said switch, afirst control circuit including 1 said first contact and a front contactof said first track relay for controlling said control relay, a secondcontrol circuit including said second contact and a front contact. ofsaid second track relay for controlling said control relay, a 3, signalfor indicating the condition of said'tracks, signal controlling meansfor causing said signal to display clear and stop indications, and aslow-acting contact adapted to be closed when said signal controllingmeans is actuated to cause said signal to display a stop indication forcontrolling said control relay independently of said first and secondcontrol circuits,

, '7. In combination, a railway track, a second railway track, a trackswitch connecting said 1 second track with said first track and which inits normal position directs trafiic movements along said first trackonly but which in its reverse position directs traiiic movements alongsaid first track to or from said second track, a signal for governingtrains approaching said switch in the facing direction, a circuitcontrolled by said switch'in its normal position and by traflicconditions on said first track beyond said switch for controlling saidsignal, a second circuit controlled by said switch in its reverseposition and by traffic conditions on said second track for controllingsaid signal, and means for preventing an operation of said switch fromone oi its positions to the other while said signal is controlled toindicate proceed if trafiic conditions on that track beyond the switchto which traffic would be directed by such operation of the switch aresuch as to cause said signal to indicate stop.

8. In combination, a railway track, a second railway track, a trackswitch connecting said second track with said first track and which inits normal position directs traffic movements along said first trackonly but which in its reverse position directs trafiic movements alongsaid first track to or from said second track, a signal for governingtrains approaching said switch in the facing direction, a circuitcontrolled by said switch in its normal position and by trafficconditions on said first track beyond said switch for controlling saidsignal, a second circuit controlled by said switch in its reversepositicn and by traflic conditions on said second track for controllingsaid signal, and means for delaying for a measured period of time anoperation of said switch from one of its positions to the other iftrafiic conditions on that track beyond the switch to which trafficwould be directed by such operation of the switch are such as to causesaid signal to indicate stop.

9. In combination, a stretch of railway track comprising a switchsection and a second section, a second stretch of track including athird section, a switch in said switch section connecting said secondstretch with said first stretch, a switch lever having a normal and areverse contact closed in normal and reverse positions respectively ofsaid lever, means controlled by said leverfor operating said switch toits normal position for directing trafiic movements along said firststretch only or to its reverse position for directing trafiic movementsto or from said sec ond stretch according as said lever is placed in itsnormal or its reverse position respectively, a locking relay, a circuitcontrolled by said normal lever contact and by traffic conditions insaid third section for controlling said relay, a second circuitcontrolled by said reverse lever contact and by trafiic conditions insaid second section for controlling said relay, a manually controllableslow-acting device, a third circuit controlled by said slow-actingdevice for controlling said relay, and meanscontrolled by said relay forcontrolling said lever.

10. In combination, a stretch of railway track comprising a switchsection and a second section, a second stretch of track including athird section, a switch in said switch section connecting said secondstretch with said first j stretch, a switch lever having a normal and areverse contact closed in normal and reverse positions respectively ofsaid lever, means controlled by said lever for operating said switch toits normal position for directing trafiic movements along said firststretch only or to its reverse position for directing trafiic movementsto or from said second stretch according as said lever is placed in itsnormal or its reverse position respectively, a locking relay, a circuitcontrolled by said normal lever contact and by traffic conditions insaid third section for controlling said relay, a second circuitcontrolled by said reverse lever contact and by traific conditions insaid second section for controlling said relay, a slow-acting devicecontrolled by traffic conditions in said first stretch in the directionfrom said switch from which trains approach when facing said switch, athird circuit controlled by said slow-acting device for controlling saidrelay, and means controlled by said relay for controlling said lever.

11. In combination, a stretch of railway track comprising a switchsection and a second section, a second stretch of track includinga thirdsection, a switch in said switch section connecting said second stretchwith said first stretch, a switch lever having a normal and a reversecon tact closed in normal and reverse positions respectively of saidlever, means controlled by said lever for operating said switch to itsnormal position for directing trafiic movements along said first stretchonly 01' to its reverse position for directing trafiic movements to orfrom said second stretch according as said lever is placed in its normalor its reverse position respectively, a locking relay, a circuitcontrolled by said normal lever contact and by traffic conditions insaid third section for controlling said relay, a second circuitcontrolled by said reverse lever contact and by trafiic conditions insaid second section for controlling said relay, a signal for governingtraffic movements toward said switch in the facing direction, a signallever having a normal and a reverse position and having a first contactwhich is closed if and only if its lever is in the reverse position anda second contact which is closed if and only if its lever is in thenormal position as well as a third contact which becomes closed if andonly if its lever has been in the normal position a measured period or"time, a third circuit controlled by the third contact of said signallever for controlling said relay, a stick circuit for controlling saidrelay controlled by the second contact of said signal lever, a circuitcontrolled by the first contact of said signal lever and by trafficconditions in said second section for controlling said signal if saidswitch is in its normal position, a circuit controlled by the firstcontact of said signal lever and by traffic conditions in said thirdsection for controlling said signal if said switch is in its reverseposition, and means-controlled by said relay for controlling said switchlever.

MELVIN A. PENROD.

